Fork Oil Weight

Questions and comments about converting to beefier forks..
Post Reply
User avatar
m0rie
Supporting Member I
Supporting Member I
Posts: 2220
Joined: 10:25 pm Nov 29 2004
Country:
Location: Crescent City, CA

Fork Oil Weight

Post by m0rie »

I'm going to tear down my KX forks and replace the seals and put fresh oil in the tubes this weekend. Is 5w the appropriate weight oil?
1989 KDX 200
2007 TTR-50E
User avatar
Indawoods
Creator and Founder
Creator and Founder
Posts: 9951
Joined: 09:59 am Jun 12 2003
Country:
Location: Midwest

Post by Indawoods »

If the spring rate is right and valved right ....then yeah... :razz:
*** Administrator //***
****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
User avatar
m0rie
Supporting Member I
Supporting Member I
Posts: 2220
Joined: 10:25 pm Nov 29 2004
Country:
Location: Crescent City, CA

Post by m0rie »

Only one way to find out then I suppose :grin:
1989 KDX 200
2007 TTR-50E
User avatar
KDX220PHIL
Supporting Member I
Supporting Member I
Posts: 419
Joined: 08:31 am May 19 2005
Country:
Location: Nova Scotia, Canada

Post by KDX220PHIL »

I used 7wt. Oil. The spring rate on the KX125 is slightly less than I was hoping for.

Those seals did not go in easy either, glad I have a seal driver.
User avatar
m0rie
Supporting Member I
Supporting Member I
Posts: 2220
Joined: 10:25 pm Nov 29 2004
Country:
Location: Crescent City, CA

Post by m0rie »

Oil is easy to change after the fact so i'll start with 5w and see how I like it with the (hopefully) stock valving and springs. The stock springs are .38's so they should be the same or softer spring rate then i've got in my forks currently. No seal driver here i'm going to try the PVC coupler cut in half method to drive them in.
1989 KDX 200
2007 TTR-50E
User avatar
KDX220PHIL
Supporting Member I
Supporting Member I
Posts: 419
Joined: 08:31 am May 19 2005
Country:
Location: Nova Scotia, Canada

Post by KDX220PHIL »

That should hopefully work. I don't know if my seals were out of tolerance or something but they took a considerable amount of force to get them in. Much more force than I was comfortable with, and the dust seals were even worse. They do not stick or leak, so I figure they are ok. Time will tell.
User avatar
skipro3
Gold Member
Gold Member
Posts: 4329
Joined: 11:58 pm Nov 04 2004
Country:
Location: BANNED FOR LIFE!!
Contact:

Post by skipro3 »

My preference is to get the correct weight springs so the forks are at the correct ride height and not chewing up travel with sag. Oil weight won't help with that. As far as oil volume; start at no more than 100 mm. I ended up at 120mm 5wt. I thought I saw an ebay auction for Racetech fork springs for KX. You may want to check that out. Race Tech seals are also heavy duty but they do take a bit of time to break in. New, they have quite a bit of stiction, so don't panic over that with new seals. About 100 miles to seat them proper.
Jerry

I'd rather be a smartass like carvr, than a dumbass like.... well, you fill in the blank!
User avatar
m0rie
Supporting Member I
Supporting Member I
Posts: 2220
Joined: 10:25 pm Nov 29 2004
Country:
Location: Crescent City, CA

Post by m0rie »

I'm going to start with the .38's that are in there and go up in spring rate if necessary.
1989 KDX 200
2007 TTR-50E
Post Reply